We) 
1912]- Esterly: Copepoda of the San Diego Region 28 
TABLE 16 
Number of 
Two-hour animals 
period Temperature per hour 
6-8 p.m. 16°3 2900 
2-4 a.m. 16°7 930 
8-10 p.m. 17°6 1795 
4-6 a.m. 18°7 1635 
10-12 p.m. 19°0 362 
2-4 a.m. 19°2 66 
6-8 p.m. 20°3 801 
8-10 p.m. 2025 1780 
8-10 p.m. 20°5 4050 
6-8 p.m. 2272 1020 
It is difficult to detect any relation between temperature 
and abundance in this table. Most of the large hauls were made 
before 10 p.m. but the temperatures at those times ranged 
from the lowest to the highest. In addition to the hauls in 
table 16, four others may be noted which were made in February 
of two different years: One haul, between 6 and 8 a.m. took 
4600 per hour at a temperature of 14°22; another, between 2 
and 4 p.m. took 404 per hour at 14°2; a third, made between 
4 and 6 p.m. captured at the rate of 1300 per hour when the 
temperature was 1328; the fourth, between 6 and 8 p.m. took 
360 at a temperature of 13°8. These hauls show that at low 
temperatures there is about as much variation in abundance as 
at medium and high temperatures. 
If all the surface hauls are arranged in a table there is no 
marked correlation between surface temperatures and number 
of specimens. Such a table is found in the one following 
(table 17). It is arranged on the same plan as table 14. 
